The number of discarded home electric appliances CRT TV (CRT), liquid-crystal display TV (LCD), plasma display panel TV (PDP), refrigerator, air conditioner, washing machine, microwave oven, cleaner, video cassette recorder (VCR) and (DVD) has been estimated using a population balance model. For the estimations of CRT and VCR, the effects of alternative products (LCD and PDP, and DVD, respectively) were considered. The increasing rates of the estimated number of the discarded refrigerator, the washing machine and the cleaner from 2000 to 2020 were within 5%, while those of air conditioner and microwave oven were more than 30%. The estimated number of shipped CRT and VCR were in good agreement with those of statistic values, indicating the reasonability of the estimated number of discarded LCD, PDP and DVD. As an application of the estimated data, the amount of indium included in the discarded display panel of LCD and PDP was calculated.